Predator and Reaper drones hang in the sky above Pakistan, Yemen, Iraq and Syria. Mostly they observe, search for targets — and occasionally unleash Hellfire missiles. Targets may be large gatherings of suspicious figures, convoys or training camps. They can also be private houses, and sometimes they turn out to be weddings.

The theory behind the strikes is not mass destruction, but to find militant leaders and kill them, as surgically as possible. But how effective have those efforts been? And who’s making the call on when to take a shot?

Today on War College, we talk about The Drone Papers— The Intercept’s attempts to parse through and explain America’s drone wars. To War Is Boring’s Joseph Trevithick, the nuts and bolts of targeted killings aren’t as important as the military logic that created the program.

Many feel that assassination via killer robot is unethical or immoral. Trevithick explains how, lacking the political will to start another foreign war, the Pentagon focused on high value targets. “We kill a lot of number twos,” he explains.

Assassinations may be an effective tactic but a poor strategy. To win a war, a military must strike its enemy’s center of gravity. For America’s enemies, that center of gravity is an apocalyptic ideology, not the personalities driving that ideology forward.